Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

In ultrasound (US) imaging, the reflections from the tissue interfaces are either diffuse or specular based on their sizes relative to the US signal wavelength and acoustic impedance mismatches at the interfaces. Diffuse reflections have low intensity and directivity, unlike specular reflections which have high intensity and directivity that depend on the incidence angle of the transmit signal and the interface orientation. This reduces the detection probability if the apodization in beamforming (as in conventional delay and sum) is inappropriate or the reflections are directed to the outside of the transducer aperture resulting in misdiagnosis (e.g., anisotropy). This puts forth the necessity to consider both the magnitude and direction of the reflected intensity before arriving at a definitive decision. In this work, a novel approach is proposed to represent the spatial distribution of acoustic intensity of each pixel as a vector field. The reflected intensity from each pixel to each transducer element is considered as a vector that has a magnitude and direction and varies depending on the nature of the pixel (diffuse/specular). This approach can supplement visualization, aid in transducer probe adjustment, selection of the right set of transmit angles/focus and characterization of reflections in musculoskeletal studies and needle tracking.

World University root node

Department of Electrical Engineering

2021 IEEE International Ultrasonics Symposium (IUS)

Intensity Vector Field: A Tool for Visualization and Characterisation of Tissue Reflections in High Frame Rate Ultrasound Imaging

This paper has carried out a detailed investigation on oscillatory mode information-based system inertia estimation techniques. In the first step, the critical modes of oscillation are extracted from the post-disturbance frequency deviation signal which is obtained from the phasor measurement units (PMUs). In this process, two popular methods for parameter estimation such as Estimation of Signal Parameter via Rotational Invariance Techniques (ESPRIT) and Matrix Pencil technique are deployed to extract the mode information. The investigation reveals the superiority of the Matrix Pencil method over the ESPRIT method for inertia estimation application. Once the mode information is available, an equivalent swing equation is used to estimate the inertia at any desired bus of the power system. The analysis is carried out on both Kundur's two-Area system and the IEEE-39 bus system. The results obtained demonstrate the superiority of Matrix Pencil based method over ESPRIT method for inertia estimation application. © 2021 IEEE.

2021 9th IEEE International Conference on Power Systems (ICPS)

Detailed Investigation of Mode Information based System Inertia Estimation using Synchrophasor Measurements

High-efficiency solar cells based on organometal-halide perovskites have been extensively reported. While there are many reports in literature regarding improved performance in these devices, only few reports provide detailed performance and theoretical efficiency limits in perovskite-based solar cells (PSCs). An analytical model accounting for both optical and electrical losses in a PSC has been largely unexplored. Our calculations provide a simple semi-analytical framework for the analysis of different loss mechanisms in a PSC, which enables the determination of theoretical performance and loss limits more accurately. We believe that this will aid in the design of high-performance PSCs.

2021 IEEE 16th Nanotechnology Materials and Devices Conference (NMDC)

Analysis of electrical and optical loss in perovskite solar cells using a semi-analytical model

This letter addresses an event-based state estimation for a linear discrete-time system with a remote estimator, when measurements are affected by multiplicative noise. An innovation-based scheduling scheme is used to communicate measurements from the sensor to the remote estimator. A maximum a posteriori estimator is employed to deal with multiplicative noise, enabling the recursive equations for the updated state and its covariance. The sensor to estimator communication rate is derived in terms of a predefined threshold that is used to trigger the sensor measurement. The results proposed are validated using a numerical example and Monte Carlo simulations. © 2017 IEEE.

IEEE Control Systems Letters

An Efficient Event-Based State Estimator for Linear Discrete-Time System with Multiplicative Measurement Noise

Electrochemical metallization-based two-dimension- al (2D) material memristors with vertical transport and small inter-electrode distances have been reported recently. Their device characteristics exhibit multiple conductance states with relatively low switching voltages, which make them well-suited for low power neuromorphic applications. Our work models the transport in these 2D material-based memristors, with a focus on explaining and capturing their current-voltage characteristics. The model also captures the dynamics of switching (with an emphasis on the estimation of switching energies and delays), and quantitatively captures the experimentally observed spike-time-dependent plasticity behaviour in these devices. The simulation results obtained using our model (and implemented in Verilog-A) have been validated with experimental data from multiple sources. Our work demonstrates the flexibility of including different transport mechanisms (such as, tunneling, space charge limited conduction) in a unified simulation framework. © 2002-2012 IEEE.

IEEE Transactions on Nanotechnology

Modeling of Electrochemical Metallization-Based Two-Dimensional Material Memristors for Neuromorphic Applications

A wideband angular stable linear-cross and linear-circular reflective type polarization converter has been illustrated in this work. The unitcell comprises a 45° rotated circular-arc based I-shaped resonator printed on top of a thin FR-4 grounded dielectric substrate. The proposed metasurface converts y/x- polarized incidence wave to its cross-polarization in three different frequency ranges: C, X, and Ku-bands. This design can also convert linearly polarized wave into circular polarization in C and Ku-bands along with linear-orthogonal conversion. The response is stable up to 45° (for linear-cross) and 30° (linear-circular) for both oblique incidences (TE and TM). The uniqueness of the design lies in dual-polarization conversion in the same bands and cell compactness with periodicity 0.1539 λL, and 0.0535 λL (λL refers to the longest free-space wavelength of the operational band). Authors strongly believe this design has the potential to be used in real-time application where the dual-polarization conversion (linear as well circular) has the primary need. © 2021 IEEE.

2021 IEEE 19th International Symposium on Antenna Technology and Applied Electromagnetics, ANTEM 2021

A Simple I-Shaped Wideband Linear-Linear and Linear-Circular Reflective Type Polarizer

This work presents a miniaturized angularly stable frequency selective surface (FSS) on a single layer substrate. Unit cell comprises of convoluted circular rings connected cross dipole and linear arrow headed dipole printed on both sides of the substrate. A closely spaced dual stop band resonances are obtained at 10 and 14.3 GHz with frequency ratio of 1.43. FSS shows a − 10 dB stopband bandwidth (BW) from 7.32 to 11.05 GHz (40.61%) and 12.68 to 15.97 GHz (22.97%) with >30 dB stop band rejection at center frequencies. FSS poses the features of stable performance under change in polarization and angularly stable response up to 60° incident angle. Later the proposed FSS is printed on grounded thick dielectric substrate and it shows broadband reflection type co to cross polarization conversion from 7.2 to 17.32 GHz (82.54%) with polarization conversion ratio >80% and oblique angle stability up to 35°. To the best of authors' knowledge, this is the first time in literature a single unit cell geometry with two different properties, spatial filtering on transmission and polarization conversion on reflection have been designed and analyzed in details. A finite array with size 25 × 25 of the proposed FSS is fabricated and the measured filter response shows a good agreement with simulated performance at normal and oblique incidences. The proposed FSS is used as a reflector of a dual band monopole antenna and the simulation results shows gain improvement of 5.51 and 3.8 dB at the two stopband frequencies. © 2021 Wiley Periodicals LLC.

International Journal of RF and Microwave Computer-Aided Engineering

Miniaturized dual stop band frequency selective surface with broadband linear co to cross polarization conversion ability

Hyaluronan (HA) is a naturally occurring non-sulfated glycosaminoglycan (GAG), cell-surface-associated biopolymer and is the key component of tissue extracellular matrix (ECM). Along with remarkable physicochemical properties, HA also has multifaceted biological effects that include but not limited to ECM organization, immunomodulation, and various cellular processes. Environmental cues such as tissue injury, infection or cancer change downstream signaling functionalities of HA. Unlike native HA, the fragments of HA have diversified effects on inflammation, cancer, fibrosis, angiogenesis and autoimmune response. In this review, we aim to discuss HA as a therapeutic delivery system development process, source, biophysical-chemical properties, and associated biological pathways (especially via cell surface receptors) of native and fragmented HA. We also tried to address an overview of the potential role of HA (native HA vs fragments) in the modulation of inflammation, immune response and various cancer targeting delivery applications. This review will also highlight the HA based therapeutic systems, medical devices and future perspectives of various biomedical applications were discussed in detail. © 2021 The Author(s)

Biological Sciences and Engineering

Journal of Controlled Release

Recent advances and prospects of hyaluronan as a multifunctional therapeutic system

The mechanisms of action of intravenous immunoglobulins (IVIg) in autoimmune diseases are not fully understood. The fixed duration of efficacy and noncumulative effects of IVIg in immune thrombocytopenia (ITP) and acquired von Willebrand disease (AVWD) suggest other mechanisms besides immunological ones. Additionally to the peripheral destruction of platelets in ITP, their medullary hypoproduction emerged as a new paradigm with rescue of thrombopoietin receptor agonists (TPO-RA). In an ITP mouse model, interleukin (IL)-11 blood levels increase following IVIg. IL-11 stimulates the production of platelets and other haemostasis factors; recombinant IL-11 (rIL-11) is thus used as a growth factor in post-chemotherapy thrombocytopenia. We therefore hypothesized that IVIg induces IL-11 over-production, which increases platelets, VWF and factor VIII (FVIII) levels in humans and mice. First, in an ITP mouse model, we show that IVIg or rIL-11 induces a rapid increase (72 h) in platelets, FVIII and VWF levels, whereas anti-IL-11 antibody greatly decreased this effect. Secondly, we quantify for the first time in patients with ITP, AVWD, inflammatory myopathies or Guillain–Barré syndrome the dramatic IL-11 increase following IVIg, regardless of the disease. As observed in mice, platelets, VWF and FVIII levels increased following IVIg. The late evolution (4 weeks) of post-IVIg IL-11 levels overlapped with those of VWF and platelets. These data may explain thrombotic events following IVIg and open perspectives to monitor post-IVIg IL-11/thrombopoietin ratios, and to assess rIL-11 use with or without TPO-RA as megakaryopoiesis co-stimulating factors to overcome the relative hypoproduction of platelets or VWF in corresponding autoimmune diseases, besides immunosuppressant. © 2021 British Society for Immunology

Clinical and Experimental Immunology

IVIg increases interleukin-11 levels, which in turn contribute to increased platelets, VWF and FVIII in mice and humans

Children and adolescents infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are predominantly asymptomatic or have mild symptoms compared with the more severe coronavirus disease 2019 (COVID-19) described in adults. However, SARS-CoV-2 is also associated with a widely reported but poorly understood paediatric systemic vasculitis. This multisystem inflammatory syndrome in children (MIS-C) has features that overlap with myocarditis, toxic-shock syndrome and Kawasaki disease. Current evidence indicates that MIS-C is the result of an exaggerated innate and adaptive immune response, characterized by a cytokine storm, and that it is triggered by prior SARS-CoV-2 exposure. Epidemiological, clinical and immunological differences classify MIS-C as being distinct from Kawasaki disease. Differences include the age range, and the geographical and ethnic distribution of patients. MIS-C is associated with prominent gastrointestinal and cardiovascular system involvement, admission to intensive care unit, neutrophilia, lymphopenia, high levels of IFNγ and low counts of naive CD4+ T cells, with a high proportion of activated memory T cells. Further investigation of MIS-C will continue to enhance our understanding of similar conditions associated with a cytokine storm. © 2021, Springer Nature Limited.